Dyes and pigments are important organic pollutants of the water environment. Dyes may be removed from wastewater by using one of the most efficient methods for wastewater treatment-adsorption onto porous (natural and waste) minerals or organogenie substances. Feasibility of using smectite-clay, co-occurring in brown coal deposits, for removal of direct dyes was investigated. The Freundlich linear regression model was better in modeling of sorption direct dyes onto smectite-clay; it yielded better fit of the theoretical isotherm to the experimental data. The electrostatic interactions and hydrogen bonds were shown to play the most important role in adsorption of direct dyes onto smectite-clay.

The adsorption of cadmium(ll) ions by low moor Alder Peat occurring in the overburden of brown coal deposits in Bełchatów Brown Coal Mine was investigated under dynamic conditions. Cadmium(ll) ions were applied to the column in aqueous solutions containing either cadmium sulfate or cadmium chloride. Solutions were also prepared containing cadmium ions alone or in combination with zinc(ll) and copper(ll) ions. The peat used as the adsorbent in this study had a high capacity for adsorbing the ions tested. The cadmium adsorbing capacity of the peat was significantly affected by pH, the anions present in the solution, and other cations present in the solution. The cadmium adsorbing capacity of the peat was significantly lower in the presence of other metal cations such as zinc(l l) and copper(l l), because these cations effectively compete with cadmium ions for binding sites on the peat. Peat can be recommended for purification processes designed to remove cadmium ions. Because cadmium ions arc predominantly loosely bound to the peat, they are easily extracted. This means that the cadmium adsorbing capacity of the peat is regenerated so that it can be used in further purification cycles.

The aim of this paper is to present characteristics, toxicity and environmental behavior of nanoparticles (NPs) (silver, copper, gold, zinc oxide, titanium dioxide, iron oxide) that most frequently occur in consumer products. In addition, NPs are addressed as the new aquatic environmental pollutant of the 21st century. NPs are adsorbed onto particles in the aquatic systems (clay minerals, fulvic and humic acids), or they can adsorb environmental pollutants (heavy metal ions, organic compounds). Nanosilver (nAg) is released from consumer products into the aquatic environment. It can threaten aquatic organisms with high toxicity. Interestingly, copper nanoparticles (Cu-NPs) demonstrate higher toxicity to bacteria and aquatic microorganisms than those of nanosilver nAg. Their small size and reactivity can cause penetration into the tissues and interfere with the metabolic systems of living organisms and bacterial biogeochemical cycles. The behavior of NPs is not fully recognized. Nevertheless, it is known that NPs can agglomerate, bind with ions (chlorides, sulphates, phosphates) or organic compounds. They can also be bound or immobilized by slurry. The NPs behavior depends on process conditions, i.e. pH, ionic strength, temperature and presence of other chemical compounds. It is unknown how NPs behave in the aquatic environment. Therefore, the research on this problem should be carried out under different process conditions. As for the toxicity, it is important to understand where the differences in the research results come from. As NPs have an impact on not only aquatic organisms but also human health and life, it is necessary to recognize their toxic doses and know standards/regulations that determine the permissible concentrations of NPs in the environment.

The pesticide persistence, in particular in soils, often significantly exceeding the declarations of their manufacturers is surprising. There are many publications devoted to the explanation of this phenomenon in the field literature, but the diverse research methodologies used may lead to the ambiguous conclusions. On the basis of the collected literature, the attempt was made to systematize the available information on the interactions of commonly used groups of pesticides with individual soil components. The complex mechanisms of interactions between pesticides and soil based on van der Waals forces, ionic and covalent bonding, ligand exchange and charge transfer complexes formation were demonstrated. It was also proved that the nature of interactions is strictly dependent on the structure of the pesticide molecule. The conclusion of the review may contribute to the choice of plant protection products that, in addition to their effectiveness, are as little ballast for the environment as possible.